These vases are made between 1920 and 1938 in what was then the country of Czechoslovakia. I have been told the country was not a happy marriage between the Czech and the Slovaks, that's why you see the hyphenated "Czecho-slovakia" signature on many of the glass pieces. These vases were easy to produce: Blow a balloon with a base glass, decorate it, and sometimes add a crystal top coat or acid bath to create a satin or flashed effect. I believe these vases were made by many glass houses in the bohemian region although dealers like to give credit to Wilhelm Kralik. The first Ball vase to your left is the most common, I have seen at least 60 from antique shows to flea markets. The marquetry (second pic. bottom right) is so complex it has 5 layers. The rarest has to be the polka dot (last pic) it has hand applied dollops of red glass between melon stripes. Thank you and happy hunting...